Infrarot‐Spektren von Cyclanen und Cyclanonen. III. Flüssigkeits‐ und Festkörperspektren der Cyclanone

The infrared spectra of a homologous series of cyclanones (CH 2 ) n–1 CO with n = 5…l5 have been investigated in the rocksalt region at temperatures between −180° … + 60° in liquid and solid state. Each of these cyclanones shows at least two infrared spectra, which transform into each other either at the melting point (n = 5, 8, 10, 11, 12, 14) or at a first order transition point (n = 6, 7, 9, 13, 15). The last group exists in two solid phases (sI) and (sII). The infrared spectra of the liquid phase and the solid phase (sI) are almost identical, indicating thereby that in these two phases the cyclanone molecules have similar freedom of orientation and exist probably in a number of conformations.